:root{
  --bg:#eef2f9;
  --bg-deep:#dfe7f4;
  --card:#ffffff;
  --ink:#101a2e;
  --ink-soft:#2b3a56;
  --muted:#66748d;
  --blue:#1b6ff0;
  --blue-deep:#0b3fa8;
  --blue-soft:#e8f1ff;
  --green:#0a9a6d;
  --green-soft:#e6f8f1;
  --red:#c2373c;
  --red-soft:#fdeeee;
  --amber:#a4700a;
  --amber-soft:#fff6e2;
  --line:#d5dfee;
  --line-soft:#e7edf7;
  --radius-xl:26px;
  --radius-lg:20px;
  --radius-md:14px;
  --radius-sm:11px;
  --shadow-sm:0 2px 6px rgba(16,26,46,.05),0 1px 2px rgba(16,26,46,.04);
  --shadow-md:0 12px 28px -12px rgba(16,26,46,.22),0 3px 10px rgba(16,26,46,.06);
  --shadow-lg:0 30px 60px -28px rgba(16,26,46,.34),0 8px 22px rgba(16,26,46,.08);
  --ease:cubic-bezier(.22,.61,.36,1);
}

*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
html,body{
  margin:0;min-height:100%;
  font-family:"Segoe UI Variable Text","Segoe UI",Inter,system-ui,-apple-system,Arial,"Noto Sans Arabic","Noto Kufi Arabic",sans-serif;
  color:var(--ink);
  background-color:var(--bg);
  background-image:
    radial-gradient(1100px 620px at 8% -12%, rgba(27,111,240,.16), transparent 62%),
    radial-gradient(900px 560px at 105% 4%, rgba(10,154,109,.11), transparent 60%),
    radial-gradient(700px 700px at 50% 118%, rgba(27,111,240,.09), transparent 60%),
    repeating-linear-gradient(0deg, rgba(16,26,46,.028) 0 1px, transparent 1px 62px),
    repeating-linear-gradient(90deg, rgba(16,26,46,.028) 0 1px, transparent 1px 62px);
  background-attachment:fixed;
  overflow-x:hidden;
}
body{overflow-y:auto;line-height:1.6;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
h1,h2,h3,h4{line-height:1.22;letter-spacing:-.015em;margin:0}
p{margin:0}
button,input,textarea,select{font:inherit}
img{max-width:100%}
::selection{background:rgba(27,111,240,.2)}
a{color:var(--blue)}

.wrap{max-width:1200px;margin:0 auto;padding:26px 22px 40px;position:relative}
.wrap::before,.wrap::after{
  content:"";position:absolute;pointer-events:none;z-index:0;
  border-radius:50%;filter:blur(58px);opacity:.5;
}
.wrap::before{width:340px;height:340px;top:-120px;inset-inline-start:-140px;background:radial-gradient(circle,rgba(27,111,240,.35),transparent 66%)}
.wrap::after{width:300px;height:300px;top:220px;inset-inline-end:-160px;background:radial-gradient(circle,rgba(10,154,109,.28),transparent 66%)}
.wrap > *{position:relative;z-index:1}

/* ---------------------------------------------------------------- header */
.top{
  display:flex;align-items:center;justify-content:space-between;gap:16px;
  margin-bottom:26px;padding:14px 18px;
  background:rgba(255,255,255,.78);
  border:1px solid rgba(255,255,255,.9);
  border-radius:var(--radius-lg);
  box-shadow:var(--shadow-sm);
  backdrop-filter:blur(14px) saturate(1.4);
  -webkit-backdrop-filter:blur(14px) saturate(1.4);
}
.brand{
  font-weight:900;font-size:21px;letter-spacing:-.02em;
  display:flex;align-items:center;gap:12px;white-space:nowrap;
  color:var(--ink);
}
.brand-logo{width:86px;height:86px;object-fit:contain;flex:none;border-radius:18px;border:2px solid rgba(212,170,55,.9);background:#0b4fba;box-shadow:0 10px 26px -10px rgba(16,26,46,.42),0 0 0 4px rgba(255,255,255,.82)}
.brand::before{display:none}

.langs{display:flex;gap:6px;flex-wrap:wrap;padding:5px;border-radius:14px;background:var(--bg-deep);border:1px solid var(--line-soft)}
.langs button{
  border:1px solid transparent;background:transparent;color:var(--ink-soft);
  border-radius:10px;padding:8px 15px;cursor:pointer;font-weight:700;font-size:14.5px;
  transition:background .18s var(--ease),color .18s var(--ease),box-shadow .18s var(--ease);
}
.langs button:hover{background:rgba(255,255,255,.85);color:var(--blue-deep)}
.langs button.active{
  background:#fff;color:var(--blue-deep);
  box-shadow:0 2px 6px rgba(16,26,46,.12),inset 0 -2px 0 var(--blue);
}

/* ---------------------------------------------------------------- hero */
.hero{
  position:relative;overflow:hidden;
  background:linear-gradient(150deg,#fff 0%,#f4f8ff 52%,#e9f1ff 100%);
  border:1px solid rgba(255,255,255,.9);
  border-radius:var(--radius-xl);
  padding:clamp(28px,5vw,54px);
  box-shadow:var(--shadow-lg);
  margin-bottom:22px;
  isolation:isolate;
}
.hero::before{
  content:"";position:absolute;inset:0;z-index:-1;opacity:.9;
  background-image:
    linear-gradient(rgba(27,111,240,.075) 1px,transparent 1px),
    linear-gradient(90deg,rgba(27,111,240,.075) 1px,transparent 1px);
  background-size:44px 44px,44px 44px;
  mask-image:radial-gradient(circle at 78% 30%,#000 12%,transparent 72%);
  -webkit-mask-image:radial-gradient(circle at 78% 30%,#000 12%,transparent 72%);
}
.hero::after{
  content:"";position:absolute;z-index:-1;inset-inline-end:-70px;top:-90px;
  width:min(48vw,470px);aspect-ratio:1;border-radius:50%;
  background:conic-gradient(from 200deg,rgba(27,111,240,.32),rgba(10,154,109,.2),rgba(27,111,240,.05),rgba(27,111,240,.32));
  filter:blur(4px);opacity:.5;
  animation:spin 34s linear infinite;
}
@keyframes spin{to{transform:rotate(1turn)}}
.hero h1{
  font-size:clamp(30px,5.4vw,58px);font-weight:900;letter-spacing:-.03em;
  background:linear-gradient(104deg,var(--ink) 6%,var(--blue-deep) 58%,var(--blue) 96%);
  -webkit-background-clip:text;background-clip:text;color:transparent;
  padding-bottom:.08em;
}
[dir=rtl] .hero h1{background:linear-gradient(256deg,var(--ink) 6%,var(--blue-deep) 58%,var(--blue) 96%);
  -webkit-background-clip:text;background-clip:text}
.hero p{color:var(--muted);font-size:clamp(16px,1.6vw,19px);margin-top:12px;max-width:60ch}
.hero .rule{
  height:3px;width:74px;border-radius:99px;margin-top:20px;
  background:linear-gradient(90deg,var(--blue) 60%,rgba(27,111,240,0));
}

/* ---------------------------------------------------------------- banner */
.banner{
  display:flex;align-items:flex-start;gap:11px;
  border:1px solid #f0d69a;background:linear-gradient(180deg,#fffaf0,#fff6e2);
  color:var(--amber);border-radius:var(--radius-md);
  padding:13px 16px;margin-bottom:18px;font-weight:600;box-shadow:var(--shadow-sm);
}
.banner::before{
  content:"!";font-weight:900;flex:none;width:22px;height:22px;border-radius:50%;
  display:grid;place-items:center;background:var(--amber);color:#fff;font-size:14px;
}

/* ------------------------------------------------------- choice sections */
.sections{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:20px}
.section{
  position:relative;overflow:hidden;
  background:var(--card);border:1px solid var(--line-soft);
  border-radius:var(--radius-xl);padding:26px 26px 28px;
  box-shadow:var(--shadow-sm);cursor:pointer;
  transition:transform .28s var(--ease),box-shadow .28s var(--ease),border-color .28s var(--ease);
}
.section::before{
  content:"";position:absolute;inset-inline:0;top:0;height:4px;
  background:linear-gradient(90deg,var(--blue),var(--blue-deep) 55%,var(--green));
  transform:scaleX(0);transform-origin:left center;
  transition:transform .38s var(--ease);
}
[dir=rtl] .section::before{transform-origin:right center}
.section::after{
  content:"";position:absolute;inset-inline-end:-60px;bottom:-70px;
  width:200px;height:200px;border-radius:50%;opacity:0;
  background:radial-gradient(circle,rgba(27,111,240,.16),transparent 68%);
  transition:opacity .3s var(--ease);
}
.section:hover,.section:focus-visible{transform:translateY(-5px);box-shadow:var(--shadow-md);border-color:#c9daf8}
.section:hover::before,.section:focus-visible::before{transform:scaleX(1)}
.section:hover::after,.section:focus-visible::after{opacity:1}
.section h2{
  font-size:21.5px;font-weight:850;margin-bottom:10px;
  display:flex;align-items:center;gap:12px;
}
.section h2::after{
  content:"";width:30px;height:30px;border-radius:10px;flex:none;margin-inline-start:auto;
  background-color:rgba(27,111,240,.12);
  background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%231b6ff0' stroke-width='2.4' stroke-linecap='round' stroke-linejoin='round'><path d='M5 12h14M13 6l6 6-6 6'/></svg>");
  background-repeat:no-repeat;background-position:center;background-size:16px;
  transition:transform .28s var(--ease),background-color .2s var(--ease);
}
[dir=rtl] .section h2::after{transform:scaleX(-1)}
.section:hover h2::after{transform:translateX(3px);background-color:rgba(27,111,240,.2)}
[dir=rtl] .section:hover h2::after{transform:scaleX(-1) translateX(3px)}
.section p{color:var(--muted);line-height:1.68;font-size:15.5px}

/* ------------------------------------------------------------- workspace */
.workspace{display:none;margin-top:22px}
.workspace.active{display:block;animation:rise .4s var(--ease)}
@keyframes rise{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:none}}

.panel{
  position:relative;background:var(--card);border:1px solid var(--line-soft);
  border-radius:var(--radius-lg);padding:22px;margin-bottom:18px;box-shadow:var(--shadow-sm);
}
.panel h2{font-size:19px;font-weight:850;margin-top:14px}
.panel h3{font-size:18px;font-weight:850;margin-top:14px;color:var(--ink-soft)}

/* --------------------------------------------------------------- buttons */
.btn,.chip,.hw-tab{
  border:1px solid var(--line);background:linear-gradient(180deg,#fff,#f7f9fd);
  color:var(--ink-soft);border-radius:var(--radius-sm);
  padding:11px 16px;cursor:pointer;font-weight:750;font-size:15px;
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  box-shadow:0 1px 2px rgba(16,26,46,.05);
  transition:transform .12s var(--ease),box-shadow .2s var(--ease),background .2s var(--ease),
             border-color .2s var(--ease),color .2s var(--ease);
}
.btn:hover,.chip:hover,.hw-tab:hover{
  border-color:#b9d1f6;color:var(--blue-deep);
  background:linear-gradient(180deg,#fff,#edf4ff);
  box-shadow:0 6px 16px -10px rgba(27,111,240,.75);
}
.btn:active,.chip:active,.hw-tab:active{transform:translateY(1px)}
.btn.primary{
  background:linear-gradient(135deg,var(--blue) 0%,var(--blue-deep) 100%);
  border-color:var(--blue-deep);color:#fff;
  box-shadow:0 10px 22px -12px rgba(11,63,168,.95),inset 0 1px 0 rgba(255,255,255,.28);
}
.btn.primary:hover{background:linear-gradient(135deg,#2a7ef7,#0a3a99);color:#fff;border-color:var(--blue-deep);
  box-shadow:0 14px 28px -12px rgba(11,63,168,.95)}
.btn[disabled],.chip[disabled],.hw-tab[disabled]{opacity:.55;cursor:not-allowed;transform:none;box-shadow:none}
.btn[aria-busy="true"]::after{
  content:"";width:14px;height:14px;border-radius:50%;flex:none;
  border:2px solid currentColor;border-top-color:transparent;animation:spin .7s linear infinite;
}
:focus-visible{outline:3px solid rgba(27,111,240,.45);outline-offset:2px;border-radius:8px}

/* ---------------------------------------------------------------- inputs */
input,textarea,select{
  width:100%;border:1px solid var(--line);border-radius:var(--radius-sm);
  padding:13px 15px;font:inherit;color:var(--ink);
  background:linear-gradient(180deg,#fbfcfe,#fff);
  box-shadow:inset 0 1px 2px rgba(16,26,46,.03);
  transition:border-color .18s var(--ease),box-shadow .18s var(--ease),background .18s var(--ease);
}
input::placeholder,textarea::placeholder{color:#93a1b8}
input:hover,textarea:hover,select:hover{border-color:#c2d4ef}
input:focus,textarea:focus,select:focus{outline:none;border-color:var(--blue);background:#fff;box-shadow:0 0 0 4px rgba(27,111,240,.13)}
select{
  appearance:none;cursor:pointer;padding-inline-end:38px;font-weight:600;
  background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2366748d' stroke-width='2.6' stroke-linecap='round' stroke-linejoin='round'><path d='M6 9l6 6 6-6'/></svg>");
  background-repeat:no-repeat;background-position:right 13px center;background-size:15px;
}
[dir=rtl] select{background-position:left 13px center}
textarea{min-height:118px;resize:vertical;line-height:1.62}

.row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
.grow{flex:1;min-width:220px}
.w-auto{width:auto;min-width:150px}
.mt-16{margin-top:16px}
.mt-14{margin-top:14px}

/* ---------------------------------------------------------------- chips */
.levels{display:flex;gap:8px;flex-wrap:wrap;margin-top:14px}
.chip{border-radius:99px;padding:9px 17px;font-size:14.5px}
#levels,#similarLevels{
  counter-reset:lvl;padding:8px;border-radius:16px;
  background:linear-gradient(180deg,#f7f9fd,#eef3fb);border:1px dashed var(--line);
}
.chip::before{
  counter-increment:lvl;content:counter(lvl);flex:none;
  width:20px;height:20px;border-radius:50%;display:grid;place-items:center;
  font-size:11.5px;font-weight:800;color:var(--blue-deep);
  background:rgba(27,111,240,.13);
  transition:background .2s var(--ease),color .2s var(--ease);
}
.chip.active{
  background:linear-gradient(135deg,#fff,#e8f1ff);
  border-color:#9cc2f8;color:var(--blue-deep);
  box-shadow:0 8px 18px -12px rgba(27,111,240,.95),inset 0 0 0 1px rgba(255,255,255,.7);
}
.chip.active::before{background:var(--blue);color:#fff}

/* ----------------------------------------------------------- lesson grid */
.lesson-grid{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,.85fr);gap:18px;align-items:start}
.content{line-height:1.82;white-space:pre-wrap;word-wrap:break-word;color:var(--ink-soft);font-size:16px}
.muted{color:var(--muted)}
#lessonText,#exampleText,#hwResult{
  padding:16px 18px;border-radius:var(--radius-md);
  background:linear-gradient(180deg,#fbfcfe,#f7fafd);
  border:1px solid var(--line-soft);
  border-inline-start:3px solid rgba(27,111,240,.32);
}
#lessonText:empty,#exampleText:empty{display:none}
.solution{padding:2px 0}

/* --------------------------------------------------------------- status */
.status{
  margin-top:12px;padding:12px 15px;border-radius:var(--radius-sm);
  background:linear-gradient(180deg,#f4f7fc,#eef3fa);
  border:1px solid var(--line-soft);color:var(--ink-soft);font-weight:600;
  display:flex;align-items:center;gap:10px;box-shadow:var(--shadow-sm);
  animation:fade .25s var(--ease);
}
@keyframes fade{from{opacity:0}to{opacity:1}}
.status:empty{display:none}
.status::before{
  content:"";width:15px;height:15px;border-radius:50%;flex:none;
  border:2px solid rgba(27,111,240,.32);border-top-color:var(--blue);
  animation:spin .75s linear infinite;
}
.status.ok::before,.status.err::before{
  animation:none;border:none;border-radius:6px;width:16px;height:16px;
  background-repeat:no-repeat;background-position:center;background-size:12px;
}
.status.ok{background:linear-gradient(180deg,#f0fbf6,#e6f8f1);border-color:#bfe9d8;color:#07654a}
.status.ok::before{background-color:var(--green);
  background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='3.4' stroke-linecap='round' stroke-linejoin='round'><path d='M4 12.5l5.5 5.5L20 6.5'/></svg>")}
.status.err{background:linear-gradient(180deg,#fdf2f2,#fdeeee);border-color:#f3caca;color:var(--red)}
.status.err::before{background-color:var(--red);
  background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='3.2' stroke-linecap='round'><path d='M6 6l12 12M18 6L6 18'/></svg>")}

/* -------------------------------------------------------------- practice */
.tools{display:flex;gap:9px;flex-wrap:wrap;margin-top:16px}
.exercise{
  font-size:17.5px;line-height:1.72;white-space:pre-wrap;font-weight:600;color:var(--ink);
  padding:16px 18px;border-radius:var(--radius-md);
  background:linear-gradient(180deg,#fff,#f6f9ff);
  border:1px solid var(--line-soft);
  box-shadow:inset 0 0 0 1px rgba(255,255,255,.8);
}
.exercise:empty{display:none}
.answer-row{display:flex;gap:10px;margin-top:14px}
.answer-row input{flex:1}

/* --------------------------------------------------------------- mastery */
.mastery{
  height:12px;border-radius:99px;overflow:hidden;margin-top:12px;
  background:repeating-linear-gradient(90deg,rgba(16,26,46,.06) 0 2px,transparent 2px 25%),
             linear-gradient(180deg,#e7ecf5,#dfe6f1);
  box-shadow:inset 0 1px 3px rgba(16,26,46,.13);
}
.mastery span{
  display:block;height:100%;width:0;border-radius:99px;position:relative;overflow:hidden;
  background:linear-gradient(90deg,var(--green),#37c79a);
  box-shadow:0 0 14px rgba(10,154,109,.55);
  transition:width .55s var(--ease);
}
.mastery span::after{
  content:"";position:absolute;inset:0;
  background:linear-gradient(90deg,transparent,rgba(255,255,255,.55),transparent);
  animation:shine 2.4s linear infinite;
}
@keyframes shine{from{transform:translateX(-100%)}to{transform:translateX(100%)}}
#masteryText{font-weight:800;font-size:15px;color:var(--green);margin-top:8px}

/* ----------------------------------------------------------------- tabs */
.hw-tabs{
  display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;
  margin:18px 0;padding:8px;border-radius:18px;
  background:linear-gradient(180deg,#f7f9fd,#eef3fb);border:1px solid var(--line-soft);
}
.hw-tab{border-radius:var(--radius-md);padding:15px 14px;font-weight:800;flex-direction:column;gap:10px;font-size:14.5px}
.hw-tab::before{
  content:"";width:34px;height:34px;border-radius:11px;background-color:#dbe6f7;
  background-repeat:no-repeat;background-position:center;background-size:19px;
  transition:background-color .2s var(--ease),transform .25s var(--ease);
}
.hw-tab[data-mode="type"]::before{background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%230b3fa8' stroke-width='2.2' stroke-linecap='round' stroke-linejoin='round'><path d='M4 7h16M4 12h10M4 17h7'/></svg>")}
.hw-tab[data-mode="upload"]::before{background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%230b3fa8' stroke-width='2.2' stroke-linecap='round' stroke-linejoin='round'><path d='M12 16V4M7 9l5-5 5 5M4 16v2.5A2.5 2.5 0 006.5 21h11a2.5 2.5 0 002.5-2.5V16'/></svg>")}
.hw-tab[data-mode="camera"]::before{background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%230b3fa8' stroke-width='2.2' stroke-linecap='round' stroke-linejoin='round'><path d='M3 8.5A2.5 2.5 0 015.5 6h1.2l1-1.8h6.6l1 1.8h1.2A2.5 2.5 0 0119 8.5v8A2.5 2.5 0 0116.5 19h-11A2.5 2.5 0 013 16.5z'/><circle cx='11' cy='12.5' r='3.2'/></svg>")}
.hw-tab:hover::before{transform:translateY(-2px)}
.hw-tab.active{
  background:linear-gradient(135deg,#fff,#e8f1ff);border-color:#9cc2f8;color:var(--blue-deep);
  box-shadow:0 12px 26px -16px rgba(27,111,240,.95),inset 0 0 0 1px rgba(255,255,255,.75);
}
.hw-tab.active::before{background-color:var(--blue);background-size:17px;
  background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='2.2' stroke-linecap='round' stroke-linejoin='round'><path d='M4 7h16M4 12h10M4 17h7'/></svg>")}
.hw-tab.active[data-mode="upload"]::before{background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='2.2' stroke-linecap='round' stroke-linejoin='round'><path d='M12 16V4M7 9l5-5 5 5M4 16v2.5A2.5 2.5 0 006.5 21h11a2.5 2.5 0 002.5-2.5V16'/></svg>")}
.hw-tab.active[data-mode="camera"]::before{background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='2.2' stroke-linecap='round' stroke-linejoin='round'><path d='M3 8.5A2.5 2.5 0 015.5 6h1.2l1-1.8h6.6l1 1.8h1.2A2.5 2.5 0 0119 8.5v8A2.5 2.5 0 0116.5 19h-11A2.5 2.5 0 013 16.5z'/><circle cx='11' cy='12.5' r='3.2'/></svg>")}

/* ----------------------------------------------------------- image stage */
.image-stage{
  position:relative;margin-top:16px;
  border:2px dashed #c7d6ea;border-radius:var(--radius-lg);
  min-height:230px;display:flex;align-items:center;justify-content:center;
  overflow:hidden;padding:14px;
  background:linear-gradient(180deg,#fbfcfe,#f4f8fd);
  transition:border-color .2s var(--ease);
}
.image-stage:hover{border-color:#9cc2f8}
.image-stage img{
  display:block;border-radius:var(--radius-md);max-width:100%;max-height:520px;
  transform-origin:center center;
  box-shadow:0 18px 40px -22px rgba(16,26,46,.55);
  transition:transform .3s var(--ease);
}
.image-stage.quarter img{max-height:100%;max-width:300px}
.image-stage span{color:var(--muted);font-weight:600}
.hw-actions{display:flex;gap:9px;flex-wrap:wrap;margin-top:14px}
.ocrbox{
  margin-top:18px;padding:16px;border-radius:var(--radius-md);
  background:linear-gradient(180deg,#fbfcfe,#f5f9fd);border:1px solid var(--line-soft);
}
.ocrbox label{display:block;margin-bottom:9px;font-size:15px}
.ocrbox strong{color:var(--ink-soft)}

/* -------------------------------------------------------------- solution */
.solution h4{
  font-size:15px;font-weight:850;text-transform:uppercase;letter-spacing:.06em;
  color:var(--blue-deep);margin:20px 0 10px;display:flex;align-items:center;gap:9px;
}
.solution h4:first-child{margin-top:6px}
.solution h4::before{content:"";width:5px;height:16px;border-radius:99px;background:linear-gradient(180deg,var(--blue),var(--blue-deep))}
.solution ol{margin:0;padding:0;list-style:none;counter-reset:step}
.solution ol li{
  position:relative;counter-increment:step;
  padding:12px 16px 12px 52px;margin-bottom:10px;
  border-radius:var(--radius-md);
  background:linear-gradient(180deg,#fff,#f8fbff);
  border:1px solid var(--line-soft);line-height:1.75;
}
[dir=rtl] .solution ol li{padding:12px 52px 12px 16px}
.solution ol li::before{
  content:counter(step);position:absolute;inset-inline-start:14px;top:12px;
  width:24px;height:24px;border-radius:9px;display:grid;place-items:center;
  font-size:12.5px;font-weight:850;color:#fff;
  background:linear-gradient(135deg,var(--blue),var(--blue-deep));
  box-shadow:0 6px 12px -8px rgba(27,111,240,.95);
}
.solution .final{
  margin-top:16px;padding:15px 18px;border-radius:var(--radius-md);
  background:linear-gradient(135deg,#eefbf5,#e2f7ee);
  border:1px solid #b9e7d5;border-inline-start:4px solid var(--green);
  color:#06614a;font-weight:800;font-size:16.5px;
  box-shadow:0 10px 24px -18px rgba(10,154,109,.9);
}
.solution .verify{
  margin-top:10px;padding:12px 16px;border-radius:var(--radius-md);
  background:linear-gradient(180deg,#fffaef,#fff6e2);
  border:1px solid #f0d69a;color:var(--amber);font-weight:600;
}

/* ----------------------------------------------------------------- foot */
.foot{
  margin:34px 0 6px;text-align:center;font-size:13.5px;color:var(--muted);
  display:flex;align-items:center;justify-content:center;gap:10px;
}
.foot::before,.foot::after{
  content:"";height:1px;width:min(18vw,120px);
  background:linear-gradient(90deg,transparent,var(--line),transparent);
}

.hidden{display:none!important}
.math{direction:ltr;unicode-bidi:isolate;display:inline-block}

/* ---------------------------------------------------------- responsive */
@media(max-width:900px){
  .sections,.lesson-grid{grid-template-columns:1fr}
  .lesson-grid{gap:16px}
}
@media(max-width:700px){
  .top{align-items:stretch;flex-direction:column;gap:12px;padding:14px}
  .langs{justify-content:space-between}
  .langs button{flex:1}
  .wrap{padding:16px 15px 32px}
  .hero{padding:26px 22px;border-radius:var(--radius-lg)}
  .panel{padding:18px;border-radius:18px}
  .answer-row{flex-direction:column}
  .hw-tabs{grid-template-columns:1fr}
  .hw-tab{flex-direction:row;justify-content:flex-start;padding:13px 14px}
  .w-auto{width:100%}
  .tools .btn{flex:1 1 auto}
}
@media(max-width:420px){
  .brand{font-size:18.5px}
  .brand-logo{width:64px;height:64px;border-radius:15px}
  .brand::before{width:32px;height:32px;border-radius:10px}
  .section{padding:20px}
}
@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important;scroll-behavior:auto!important}
}